Pluggable optical devices are keys to many optical fiber applications. Cost effective and reliable pluggable optical devices having low insertion loss and versatile functions are constantly demanded in optical networks. Various small form factor (SFF) pluggable optical devices have been developed and broadly deployed in Telecom and Data Center applications.
The pluggable optical device typically has one input port and one output port, which is applied to optical fiber communications. The optical signal may travel through the pluggable optical device entering to the input port and exiting from the output port of the device. In some embodiments, electronic interface is integrated in the pluggable device for system control. In some passive optical network applications, electronic control may not be required.
FIG. 1 schematically shows a Metro network 100. Network 100 comprises a plurality of nodes including a node 102. Network 100 comprises a plurality of optical signals having various wavelengths, for example, wavelengths defined in dense wavelength division multiplexing (DWDM) or WDM. For example, network 100 drops a wavelength at node 102. In other words, optical signal having a wavelength 1 is directed out from network 100, while optical signals having other wavelengths remain in the network.
A thin film filter (TFF) may transmit light having a specific wavelength band, and reflect light having wavelengths outside the specific wavelength band. An optical element comprising a thin film filter may be used to drop a wavelength from the network, which typically has two fiber pigtails at its both ends. The optical element may be easily connected to Metro network 100 using a LC connector 104 as shown schematically in FIG. 1. At least one fiber pigtail may be held by a LC connector.
The LC connector is a popular small form factor connector. This interface was developed by Lucent Technologies (hence, Lucent Connector or LC). It uses a retaining tab mechanism, similar to a phone or RJ45 connector, and the connector body resembles the square shape of other older connectors. The diameter of the ferrule of an LC connector is 1.25 mm.
FIG. 2 schematically shows a next generation passive optical network (NGPON) 200. NGPON 200 comprises a plurality of fiber-to-the-home (FTTH) sites 202. Each FTTH site 202 may require to drop a wavelength and to block the remaining wavelengths using a thin film filter. Similarly, the thin film filter element may have two fiber pigtails. At least one fiber pigtail is held in a LC connector. The thin film filter element may be connected to NGPON 200 through a LC connector 204.
In both Metro network and NGPON applications, and also other applications, pluggable optical devices having no fiber pigtails, which have small form factor and are cost effective, versatile, and easy for field deployment, are demanded. More specifically, pluggable LC adaptors compatible with LC connector jacks of a network having passive optical elements are demanded.
Corresponding reference characters indicate corresponding components throughout the several views of the drawings. Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention.